CH 4g69 Turbo conversion

Radical_Ralliart

Active Member
Hey everyone, I’ve decided I’d like to turbocharge my 2.4L CH lancer sometime next year so I want to gather as much info as possible. I’m going turbocharge a stock 4g69 with no work to the bottom end but i may do some work to the head.

I’ve estimated about a $10k-$11k budget for this conversion, i will be cheaping out where i can but certain things i can’t avoid spending more.

From my understanding engines with skinny rods like these don’t like boost coming on early, so I want to get a Pulsar 3071R turbo for this reason. I want to keep it internally gated at a boost pressure of around 7-9psi for the sake of engine longevity (or as much as you could really manage boosting an N/A engine).

I’d like to get some more input from people who have boosted 4g69’s, is there any fabrication or fitting tips i should consider?

Heres a photo of my lancer anyways
 

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Hey mate! Short and sweet of it; you need oil, coolant, exhaust, intake and tunnneeee.

Oil comes from a sandwich plate - drains into the sump. So buy a high pressure line, restrictor and a drain line. Fab up fittings.
Coolant take it from wherever, throttle heater if you have one, just keep the direction of heat flow right.
Exhaust - custom manifold, are you making your own?
Intake - Pick your intercooler, grab some cheap alloy pipe and joiners and you'll be sweet. Easier to make them and fix them later than to make it "perfect" first go.
Tune - depends how you do it and who does it tbh, but this ideally will include larger injectors, fuel pressure sensing or regulating and what not.

If you're not DIY tuning, you can save on having a WB02 installed, but I really like having mine and the gauge as a monitor for things going wrong.

The 3071 is pretty big and new is expensive... Have you considered something a bit better sized? I would personally pick something abundant second hand with a downpipe/dump pipe in the right orientation. Probably a TD05 or similar would save you a BUNCH. Bigger aint always better

Tuning and right foot will save your motor, not necessarily the turbo size. Would thoroughly recommend putting in a bunch of sensors ASAP and getting used to what the readings should be while NA. Then you can spot issues while boosted before they become explosions.

Also feel free to discuss ideas and plans here, the more we talk the better this place becomes. I owe this forum and the people a BUNCH when it comes to what got my car boosted - keep it shared and you'll be helping the next guy and so on. There are people are around who are happy to borrow ideas, ask you for help so they can show off online but wont share any of it back into the community again...
 
Hey man thanks for the info, i’ve really got to know the 4g69 pretty well thanks to a number of people on this forum including yourself.

So at the moment i’ve bought a Walbro 255lph fuel pump and ‘06 wrx STI 565cc fuel injectors (i plan on running 98 octane, not planning on e85 or race fuel)

Also bought 2.5” diameter Intercooler + piping kit for $220, not too bad for a cheap kit. I’ve been suggested by a few people to use a Pulsar 3071R turbo, a guy i know from queensland who drives a red boosted 2.4 CH is running a 2871 turbo, he mentioned that boost comes on a little too early and that he would’ve preferred a slightly bigger turbo.

From what i’ve checked out on pulsar’s website the PSR3071R seems to be a pretty good kit at a price of $995, i like that its a ball bearing turbo and its suitable for 2.5-3.0L engines (supposedly)
 
I’ve checked out RPW’s link G4X plug in standalone ecus for my car but its alot of money for ease of tuning. I’m not sure if i’d be better off saving a grand or so and buy an Adaptronic ecu
 
Hey mate! Short and sweet of it; you need oil, coolant, exhaust, intake and tunnneeee.

Oil comes from a sandwich plate - drains into the sump. So buy a high pressure line, restrictor and a drain line. Fab up fittings.
Coolant take it from wherever, throttle heater if you have one, just keep the direction of heat flow right.
Exhaust - custom manifold, are you making your own?
Intake - Pick your intercooler, grab some cheap alloy pipe and joiners and you'll be sweet. Easier to make them and fix them later than to make it "perfect" first go.
Tune - depends how you do it and who does it tbh, but this ideally will include larger injectors, fuel pressure sensing or regulating and what not.

If you're not DIY tuning, you can save on having a WB02 installed, but I really like having mine and the gauge as a monitor for things going wrong.

The 3071 is pretty big and new is expensive... Have you considered something a bit better sized? I would personally pick something abundant second hand with a downpipe/dump pipe in the right orientation. Probably a TD05 or similar would save you a BUNCH. Bigger aint always better

Tuning and right foot will save your motor, not necessarily the turbo size. Would thoroughly recommend putting in a bunch of sensors ASAP and getting used to what the readings should be while NA. Then you can spot issues while boosted before they become explosions.

Also feel free to discuss ideas and plans here, the more we talk the better this place becomes. I owe this forum and the people a BUNCH when it comes to what got my car boosted - keep it shared and you'll be helping the next guy and so on. There are people are around who are happy to borrow ideas, ask you for help so they can show off online but wont share any of it back into the community again...
With the exhaust manifold i’m thinking of getting the manifold flange made up then figure out how to route the piping in the engine bay, is it better to do a top mount or bottom mount turbo? I understand theres not a lot of room with the factory rad/fan setup + the starter motor location.

Unless i possibly do an evo half radiator setup? Not sure if the engine will still cool properly with a rad like that.
 
In regards to the PSR3071R, have a look at the compressor maps. Then have a look at maps for some smaller and larger turbos and see where the 2.4l motor is going to sit at a few RPM points. I went to a lot of trouble to make sure I got a turbo that doesnt take ages to spool. If youre still super keen on no boost below a certain RPM you could also delay boost with boost control via aftermarket ECU - keep that in mind too. Lots of ways to do something. Won’t comment on the quality of a Pulsar turbo for now. :grimacing:

Should be plenty of pump and injectors for the boost level you’re talking about - I’d recommend a fuel pressure sensor if your ECU is compatible.

Onto ECU’s, the factory one will support boost, you’ll just need to find someone to do the tuning for you or DIY. You can fit almost any aftermarket unit in - can make or have made your own patch harness. Pick an ECU based on what your tuner is comfortable with/knows well. No point dropping 5K on a Nexus if your tuner is a Link guy you know?

Pro’s and cons of turbo location as you said. Theres a thread here about a yellow 2.4 ch with a top mount by @360fab i thiiink. It fit, no real dramas. The low mount will get squishy like you say but not impossible. A good 3 core radiator will keep the car cool even in half size, so dont sweat it. Fabing your own will be time consuming but probably cost effective.
 
Trying to find cheaper TD05 turbos but i can seem to only find ones for subaru EJ’s, ideally if i can find a TD05 with a T3 flange and 5 bolt outlet that would work for me.

Another thing i can hopefully get sorted this year is buying a spare 4g69 engine and make that one the turbo engine. I’ll be buying a full genuine mitsubishi gasket set from partsouq.com, as i said before i won’t be doing any bottom end work to the engine but i will be replacing the head gasket and installing arp 2000 headstuds to prevent any head lifting issues later. That seems to be a common problem with stock 4g69’s being boosted.

With the cylinder head I’ll definitely get that refurbished for the sake of reliability, but i might also installed a cam or at the very least better valve springs
 
I guess location is a bit of a kicker for you too, I’ve got 18g and 20g td05’s for $500 within a 10 minute drive haha. See what’s available, could even be better value new, but dont be afraid to try things.

Are you fabing your own down pipe/dump?
 
I guess location is a bit of a kicker for you too, I’ve got 18g and 20g td05’s for $500 within a 10 minute drive haha. See what’s available, could even be better value new, but dont be afraid to try things.

Are you fabing your own down pipe/dump?
Unfortunately i didn’t pay attention in my highschool metalworking classes so i’m not skilled at all with welding lol

I’m probably going to have to get the entire exhaust system including the manifold made by someone, i do know a few people who have welding equipment so maybe i can give it a go
 
So i contacted pulsar about getting a 3071R with an internal wastegate and they’ve said they can only get one with a dual .72 V-band.

would it be more difficult to make the V-bands work? Or easier?
 
Manifold is gonna stinnggg, but it’ll be sweet to have something custom. V-bands require a touch more precision in the fab but if you’re paying for the work it wont be an issue.

If it’s v-band intake, just grab yourself a pre-fab inlet adaptor to regular piping so you can use silicone joiners and your pipe kit.
 
Manifold is gonna stinnggg, but it’ll be sweet to have something custom. V-bands require a touch more precision in the fab but if you’re paying for the work it wont be an issue.

If it’s v-band intake, just grab yourself a pre-fab inlet adaptor to regular piping so you can use silicone joiners and your pipe kit.
I did email the guys at pulsar about where the vbands were, they said its the turbine inlet and outlet that are .72 V-bands
 
In regards to the PSR3071R, have a look at the compressor maps. Then have a look at maps for some smaller and larger turbos and see where the 2.4l motor is going to sit at a few RPM points. I went to a lot of trouble to make sure I got a turbo that doesnt take ages to spool. If youre still super keen on no boost below a certain RPM you could also delay boost with boost control via aftermarket ECU - keep that in mind too. Lots of ways to do something. Won’t comment on the quality of a Pulsar turbo for now. :grimacing:

Should be plenty of pump and injectors for the boost level you’re talking about - I’d recommend a fuel pressure sensor if your ECU is compatible.

Onto ECU’s, the factory one will support boost, you’ll just need to find someone to do the tuning for you or DIY. You can fit almost any aftermarket unit in - can make or have made your own patch harness. Pick an ECU based on what your tuner is comfortable with/knows well. No point dropping 5K on a Nexus if your tuner is a Link guy you know?

Pro’s and cons of turbo location as you said. Theres a thread here about a yellow 2.4 ch with a top mount by @360fab i thiiink. It fit, no real dramas. The low mount will get squishy like you say but not impossible. A good 3 core radiator will keep the car cool even in half size, so dont sweat it. Fabing your own will be time consuming but probably cost effective.
With the turbo size, do you know what would be a pretty ideal size for the displacement? I don’t mind if boost comes on a bit later.

My original idea was to have a fairly large turbo so i can run it at a lower boost pressure, so i don’t put too much stress on the stock bottom end without sacrificing too much power potential
 
My personal pick would be a TD05 from an evo second hand for cheapness and if you want new & ball bearing 2867r. I'm not an "expert" and these are just my picks with about 2mins of thinking about it. You could also definitely run a td04 too.

Talking turbos have you had a look at compressor maps before? They detail everything you need to know. Airflow across the bottom and pressure ratio along the y axis, you want to consider a few points in the map corresponding to some RPM ranges of your motor at varying boost levels. You want to be in the centre island/s of the map to consider your choice effective and efficient. Looking at a map for a 3071r, your motor would be sitting pretty low in the map - not really using that turbo at all.

Airflow out of a 2.4 is considerably more than from a 1.8 or 2l sohc but not crazy until you wind the boost right up. As a ROUGH guess a 2.4 sohc should be in the same ball park as a DOHC 2l - which is why I suggested the evo turbo cause thats what an evo motor is.

Something like a 2860 would be neat and responsive, but perhaps limiting if your boost targets increase.

You're technically correct in saying that boost later is safer, BUT.. you're only after 9psi max. AND if you're going flat to the floor at 2k rpm wihtout any sympathy for your motor, was it really going to last that long anyway?
Also consider that your car is running at reduced power while not in boost with a turbo strapped on. It would suck to drive being down on power till 5k rpm no? I imagine your rev limit is 6700 and you're gonna keep or reduce it with a turbo? Right foot control can save you heaps and so can boost control. I use a responsive turbo at low boost and LOVE it. Its how all new cars operate because it gives you usable torque/power.

Ideally you'd want something that can make full boost at 3k rpm atleast and still has plenty left in it at 6k rpm - this gives you a neat power band and torque where you need it.
 
Also if you're not going forged, don't put too much effort or money into the headwork - it could all be collateral if the motor grenades :)
 
True, i still want to install arp headstuds so i dont risk a blown head gasket.

I’m not sure where to find compressor maps for different displacements, i can see the size of compressor and turbine wheels but i don’t know the airflow performance
 
I found the compressor map and exhaust flow chart for the 3071R turbo, these diagrams are from Garret but they should be almost identical to Pulsars 3071R
 

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Just wondering @SDate42 is there a comprehensive list on the forums about aftermarket parts for re-building 4g69’s? Especially what 4g63 parts will fit like main/rod bearings, conrods, pistons, oil pumps, even baffled sumps, etc, the list could go on

I found a cheap set of king main bearings for the 4g69/63 for about $70 on ebay, so it got me thinking what other performance brand parts would suit a 4g69
 
Just some quick numbers/info dump;
you need aprox 10lb per min of air for every 100hp you plan to make
pressure ratio is the inlet pressure divided by atmospheric
Left and right hand sides of the compressor map are big no-no areas. Left is surge, right is too hot.
Being under the map, I can't recall, I think its just inefficient due to shaft speed too low

So you want 7-9psi of boost? Gives you a pressure ration around 1.7ish.
4g69 makes 160hp, should double at 1bar boost, so we can say roughly that at 7-9 it wont make double but atleast 100hp extra. So for airflow we look to be around 25-30lb per min.

That sits you in the lower 1/4 of the maps for any of the turbo' we've talked about. Should give you a visual now when you look at maps. The closer to the center islands the better, too far right is hot, too left is surge. You won't hit the top of the map, don't stress!

You should be able to see the difference now, the 3071r will be in a good range at 9psi and making 250-300hp, but as you build up to those you may find it lackluster. 3071r is not as huge as I anticipated, still has a fairly good low response but I reckon you'd notice it. Small AR housing is a MUST or it'll be so slow to spool, there's such a big gap in the housing charts!

For a comparison, consider a 4g94 making 200hp at a pressure ratio of 2 for both a 3071 and a 2867 and that is a really obvious difference in turbo efficiency and makes your choice easier.
 
Just wondering @SDate42 is there a comprehensive list on the forums about aftermarket parts for re-building 4g69’s? Especially what 4g63 parts will fit like main/rod bearings, conrods, pistons, oil pumps, even baffled sumps, etc, the list could go on

I found a cheap set of king main bearings for the 4g69/63 for about $70 on ebay, so it got me thinking what other performance brand parts would suit a 4g69
Wagonmaster put together a bit of a thread with evo stuff, it's as good as you'll get. Can also read up on the evom forums but theyre a mess.

Bearings are cheap, $70 is about the going retail price. Notably bearings wont make any difference if you "Upgrade". Your oil is your bearing - bearings just set the clearance for oil. Hope that makes sense.

You could always slap together a forged setup, pistons, rods and bolts is all it would cost you, could probably do it for about 3k pending costs ect.

The real cost is in machine work and blueprinting the bottom end. It's stuff you can't DIY and makes all the difference for longevity and absolute HP, but you're talking about 80% more work/money for maybe 20% gains. It's where you gotta weigh your options. For me, spending 3k on forged gear, may aswell pay to have it all properly balanced, machined and tolerance-d, but you certainly dont have to.
 
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